Gas turbine engines are used to power aircraft, watercraft, power generators, and the like. Gas turbine engines typically include a compressor, a combustor, and a turbine. The compressor compresses air drawn into the engine and delivers high pressure air to the combustor. In the combustor, fuel is mixed with the high pressure air and is ignited. Products of the combustion reaction in the combustor are directed into the turbine where work is extracted to drive the compressor and, sometimes, an output shaft. Left-over products of the combustion are exhausted out of the turbine and may provide thrust in some applications.
Airfoils are included in the rotating blades of the turbine to capture energy from the products of the combustor. The interaction of combustion products with the airfoils heats the airfoils. Airfoils are often made from high-temperature compatible materials and/or are actively cooled by supplying relatively cool air to the airfoils. To this end, some airfoils incorporate composite materials or heat shields to withstand very high temperatures. Design and manufacture of airfoils from composite materials presents challenges because of the geometry and strength required for the parts.